Seal for floating roof tanks



NW. 2%, WW F. L. GOLDSBY ETAL SEAL FOR FLOATING ROOF TANKS m a 0 1 WFiled Nov. 26, 1945 Patented Nov- I UNI- ao srlrras"v PAr-E ,srm. roaFLOATING noor TANKS Fred L. Goldsby nd Clifford rr,-Chicago,

,Ill., assignors to ChicagoBridge & Iron pany, a corporation of IllinoisCom- Application November as, 1945, Serial No.' 630,715;

I f l This invention relates to 8 Claims. (Cl. 220-26) and particularlyto a seal for sealing the area be-- I tween the floating roofand theshell of the tank.

Floating roof tanks are used to store vol atile liquids. The roof floatson top of the stored liquid and rises and falls as the quantity ofliquid is increased and decreased. This servesto limit evaporationlosses of the liquid, as-therejis very small vapor spaceprovided. g Itis necessary in floating roof tanks that me be provided for sealing thearea between the edge.

of the roof and-the shell of the tank in order to prevent substantialevaporation losses and to prevent contamination of" the stored liquid.We have invented an improved type seal which positively seals this areaand provides a substantially gas tight cover for the surface ofthestored liquid.

The invention will be described'as related. tov the embodiments shown inthe accompanying drawings. Of the drawings Fig. 1 is the frogmentaryplan view of a storage tank embodyingably attached to the vertical edgeportion of the floating roof by means-"of flat-plates l3 attached to theroof and spaced therefrom. Theseplates have'sloping slots 14 (Fig. 3) tohold the ends l5 of the hanger arms l2. These ends. are bent I 8 areconnected by smaller pipes I8 fitted within their ends. The assembliesof pipes l6 and cylindrical sleeves ll and pipes l6 and smaller pipes I8form continuous holders around. the edge of the roof over which asealing member I9 may be held. The support is free to expand orcontract, and thus adjusts its'elf'to the shape of the shell. Othersupport .means than that shown and described may be used if desired.

The sealing member l9, which is preferably a fabric impregnated with animpervious flexible material, is attached to the edge of the roof bymeans of, for example, spaced hooks 20 that hold a rod 2| insealing'contact with the edge of the sealing member. The sealing memberextends ifromthe edgeof the roof up over the support means at the upperends of hanger arms l2, and down along the edge of the shell Ill. Theshell portion 22 of the sealing member is provided with raisedabrasion-resistant bumper strips 23, while the bottom portion 24 of thesealing member ex tends upwardly andis fastened to an annular flange 25at the edge of the floating roof to form a trough 28. This trough isfilled with a mobile weighting material such as a non-volatilenonfreezing oil of preferably higher specific gravity than the storedliquid. The top surface of the sealing liquid 26 may be above thesurface of the stored liquid, or may be level with the stored liquid,but is preferably not below the level of the liquid within the tank. Themobile weighting material may also be a granular material where thegranules flow easily over and aroundeach other. 7 a

A secondary seal is preferably provided at the topmost portion of thesealing member l9, and

this, secondary seal may be a fabric attached to the-supports by'meansofbolts 28. Immediately substantially at right angles to'the. main bodyportion of the vhanger'arms, and are arranged in this manner so that thehanger armsv may. rotate outwardly away from the roof. The slots g I4are provided so that the ends l5- of the hanger arms [2 may beeasily-inserted. If desiredthe slots may be constructed-with adownwardly extending portion t substantially the 1 middle so" that thearmwill be held at the bottom of the r downwardly extending portion.

At the top end of each hanger arm 12 there is located a substantiallyhorizontal pipe 16 attached at its midpoint to the hanger arm. In theembodiment shown in Fig. 1' the pipes are connected to each other bycylindrical sleeves I! with each end of a sleeve surrounding an end of apipe 16. In the embodiment shown inFig. 4 the pipes below the secondarysealzl there is provided a -.wide bumper strip 29 in contact with theshell Ill. -I'n order to keep the floating roof centered within theshell there are provided pairs ofupstanding bracket arms 30 spacedaround the edge of the roof with wheels 3'! rotatably held at the endsof the bracket arms 30 and in contact with the shell l0.

Although the shell I0 is usually made'eylindri .cal when erected itsometimes gets out of round.

The hanger arms 12, being rotatably mounted, will adjust themselves tothis out-of-roundness, as

. shown indotted lines in Fig. 3.

Having described our invention as related to a typical embodiments ofthe same, it is ourintention that the invention be not limited by any ofthe details of description unless otherwise speci- NT OFFICE- fled, butrather be construed broadly within its spirit and scope as set out inthe accompanying claims.

We claim:

1. A seal for a floating roof tank comprising a plurality of spacedhanger arms rotatably mounted on the side of the roof extending from theedge portion of the floating roof toward the shell of the tank, anannular carrier means supported by the hanger arms, a flexibleimpervious sealing member attached to the roof and extending from theedge of the roof'over the carrier means, down along the tank shell to apoint below the surface of the stored liquid, and up to the rOOf to forman annular trough at the bottom portion of said sealing member, and aweighting material within said annular trough.

2, The seal of claim 1 wherein the bottom edge of the flexible sealingmember is held away from the roof by an annular flange attached to theedge of the roof.

3. A seal for a floating roof tank comprising a plurality of spacedhanger arms extending upwardly from the vertical edge portion of thefloating root toward the shell of the tank, a continuous annular carriermeans attached to the outer ends of the hanger arms, aflexible'impervious sealing member attached to the edge Of the roofabove the hanger arms and extending over the carrier means, down alongthe shell to a point below the surface of the stored liquid, and up toan annular flange attached to the floating roof below the hanger arms toform an annular trough, and a mobile weighting material within saidannular trough.

4. The seal of claim 3 wherein a raised bumper strip is provided on theshell side of the sealing member opposite the carrier means and adaptedslidably to contact said shell? v 5. A seal for a floating rooi' tankcomprising a plurality of spaced hanger arms rotatably mounted on theroot and extending upwardly from the vertical edge portion oi thefloating root toward the shell of the tank, a plurality of curvedtelescoping pipe-like sections arranged in the form of an annulus andattached to the outer ends oi the hanger arms, a flexible impervioussealing member attached to the edge of the roof above the hanger armsand extending over the annulus, down along the shell to a point belowthe surface of the stored liquid and up to an annular flange attached tothe floating roof below the hanger arms to form an annular trough, saidsealing member having spaced raised bumper strips on the sealing memberadapted slidably to contact the shell and including a bumper stripopposite the annulus, and a liquid within said am, ular trough.

6. The seal of claim 5 including a secondary seal supported by theannulus and adapted to contactsaid shell above the sealing member.

FRED L. GOLDSBY. CLIFFORD M. ORR.

REFERENCES CITED The following references are of record in the tile oithis patent:

UNITED STATES PATENTS Number Name Date 1,493,344 Huif May 6, 19241,660,021 Wiggins Feb. 21, 1928 1,668,792 Wiggins May 8, 1928 2,036,372Stough Apr. 7, 1936 2,085,752 Horton et a1 July 6, 1937 2,089,645Dickmann Aug. 10, 1937 2,297,985 Rivers Oct. 6, 1942 FOREIGN PATENTSNumber Country Date 94,546 Switzerland May 1, 1922 290,443 Germany Sept.25, 1913

